Method of manufacturing continuous fastener element

ABSTRACT

A continuous fastener element including: a coupling head; upper and lower leg portions; and a connecting portion wherein surfaces of the coupling head, the leg portions, and the connecting portion are each formed as a rough surface with a plurality of recesses. Furthermore, a head surface of the coupling head of the continuous fastener element is formed to have an average roughness Ra smaller than that of outer peripheral surfaces of the leg portions. Accordingly, gloss and luster of the continuous fastener element may be easily reduced or removed. Furthermore, when the slide fastener is formed, the resistance between the coupling heads of the left and right continuous fastener elements may be made small and the left and right element rows may smoothly engage with each other or disengage from each other.

This application is a divisional of U.S. application Ser. No.13/142,890, which issued as U.S. Pat. No. 8,765,248 on Jul. 1, 2014, andwhich is a national stage application of PCT/JP2009/056336, both ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a continuous fastener element which is formedby molding synthetic resinous monofilament in a coil shape or a zigzagshape, and particularly, to a continuous fastener element whichsuppresses gloss and luster of an element surface and has new texture.

BACKGROUND ART

In general, a continuous fastener element having a coil shape or azigzag shape and used in a slide fastener is manufactured in a mannersuch that a thermoplastic synthetic resinous material is extruded tomold linear monofilament, the obtained monofilament is molded in a coilshape or a zigzag shape, and a part of the monofilament is pressed at aconstant interval to mold a coupling head.

Further, for example, Japanese Patent Application Publication No.7-63411 (Patent Document 1) or the specification of Japanese Patent No.3698562 (Patent Document 2) discloses a method or a device formanufacturing a coil-shaped continuous fastener element by moldingsynthetic resinous monofilament.

The device disclosed in Patent Document 1 includes a supply roller whichnormally supplies a constant amount of synthetic resinous monofilament,a stamp-molding portion which has a pair of molding rollersstamp-molding a coupling head or the like on the monofilament suppliedfrom the supply roller, and a coil-shaped element molding portionincluding mandrel which molds the stamp-molded monofilament into acoil-shaped continuous fastener element.

The supply roller in Patent Document 1 includes a supply pulley aroundwhich the monofilament is wound a number of times and supplies themonofilament to the stamp-molding portion, so that a constant amount ofthe monofilament may be normally supplied to the stamp-molding portionby the supply pulley.

For example, as shown in FIG. 8, a stamp-molding portion 50 includes acircular roller 51 and an annular roller 52 serving as the pair ofmolding rollers, and a recess-like tooth 54 is provided on an outerperipheral surface 53 of the circular roller 51 at a constant interval.Further, a protrusion-like tooth 56 is provided on an inner peripheralsurface 55 of the annular roller 52 at a constant interval to correspondthe position of the recess-like tooth 54 of the circular roller 51,whereby the stamp-molding process may be performed along with thecircular roller 51. Furthermore, the circular roller 51 and the annularroller 52 are configured to revolve around a mandrel to be describedlater of the coil-shaped element molding portion while they rotate.

In the stamp-molding portion 50, the circular roller 51 and the annularroller 52 are rotated, and monofilament 57 supplied from the supplyroller is guided to a gap between the outer peripheral surface 53 of thecircular roller 51 and the inner peripheral surface 55 of the annularroller 52. Accordingly, the monofilament 57 is press-molded by theprotrusion-like tooth 56 of the annular roller 52 and the recess-liketooth 54 of the circular roller 51, so that a coupling head or the likehaving a predetermined shape is formed on the monofilament 57.

The coil-shaped element molding portion includes a rod-like mandrelwhich is fixed to a mandrel holder, and the circular roller 51 and theannular roller 52 revolve around the mandrel while they rotate to windthe monofilament 57 having the coupling head molded thereon around themandrel, so that the monofilament 57 is molded in a coil shape.Furthermore, a passage is provided in the mandrel in the longitudinaldirection to allow a core thread to pass through.

Therefore, the monofilament 57 having the coupling head molded by thecircular roller 51 and the annular roller 52 of the stamp-moldingportion 50 is guided to the mandrel of the coil-shaped element moldingportion, and the circular roller 51 and the annular roller 52 revolvearound the mandrel, so that the monofilament 57 is wound around themandrel to be molded in a coil shape. Also, the core thread isdischarged from the front end of the mandrel through the passageprovided inside the mandrel, so that the coil-shaped continuous fastenerelement having the core thread inserted therethrough is manufactured.

On the other hand, the device disclosed in Patent Document 2 includes amonofilament supply portion which supplies monofilament, a windingportion which has a mandrel and winds the monofilament around themandrel to have a coil shape, and an element molding portion which moldsa coupling head or the like to have a predetermined shape on themonofilament wound around the mandrel.

The monofilament supply portion includes a large spool around which themonofilament is wound, a flier which guides the monofilament unwoundfrom the spool, and a guide roller which switches the carriage directionof the monofilament.

The winding portion includes a rotary body which has a monofilamentguide hole, a rod-like mandrel, a core thread bobbin which supplies acore thread, and a core thread drawing body which draws out the corethread from the core thread bobbin. Further, a core thread guide grooveis formed in the mandrel throughout the entire length thereof to guidethe core thread in a sliding manner.

In the winding portion, the monofilament supplied from the monofilamentsupply portion is guided to the mandrel through the monofilament guidehole of the rotary body by rotating the rotary body, so that themonofilament is wound around the mandrel to mold the monofilament in acoil shape.

The element molding portion includes a pair of screws which is disposedwith the mandrel of the winding portion interposed therebetween, upperand lower coupling head forming portions which are disposed with themandrel interposed therebetween and form a coupling head on themonofilament molded in a coil shape, and an upper leg forming portionwhich bends a part of the monofilament formed as a continuous fastenerelement upper leg portion in a step shape.

Accordingly, the monofilament wound around the mandrel is carriedforward in a coil shape with the rotation of the left and right screws.In accordance with the carriage, the coil-shaped monofilament firstreaches the coupling head forming portion, and the coupling head formingportion press-molds the monofilament at a predetermined interval, sothat a coupling head is formed on the monofilament.

Subsequently, the monofilament having the coupling head formed thereonis carried to the upper leg forming portion with the rotation of theleft and right screws, and the monofilament is punched at apredetermined interval by the upper leg forming portion, so that a stepportion is formed on a portion formed as the fastener element upper legportion. Subsequently, the core thread discharged from the front end ofthe mandrel is inserted into the coil-shaped monofilament, so that acoil-shaped continuous fastener element is manufactured which has a stepportion accommodating a sewing thread in the upper leg portion.

Incidentally, in the slide fastener having the coil-shaped continuousfastener element, a lubricating material is applied to the outerperipheral surface of the continuous fastener element in order tosmoothly slide the slider along the element row or smoothly engage theleft and right element rows with each other.

Further, Japanese Patent Application Publication No. 1-19888 (PatentDocument 3) discloses a configuration in which minute grooves orrecesses are formed on the entire outer peripheral surface (the surface)of the continuous fastener element when a lubricating material isapplied to the outer peripheral surface of the continuous fastenerelement. Furthermore, Patent Document 3 discloses an example of a methodof forming minute grooves or recesses on the outer peripheral surface ofthe continuous fastener element in a manner such that minute unevenportions are formed on an opening of a nozzle extruding monofilament,the surface of the monofilament is rubbed by an abrasive member withminute particles, or a sand blasting process of blasting minuteparticles is performed.

In this manner, when minute grooves or recesses are formed on the outerperipheral surface of the continuous fastener element, the lubricatingmaterial applied to the continuous fastener element may be buried in thegrooves or recesses, so that the lubricating material may be properlyattached to the continuous fastener element.

For this reason, for example, when the slide fastener having thecontinuous fastener element is cleaned, it is possible to prevent thelubricating material from being separated from the continuous fastenerelement even when an external force is exerted on the lubricatingmaterial applied to the continuous fastener element during the cleaningor the like or an external force is exerted on the lubricating materialdue to the contact between the coupling heads of the left and rightcontinuous fastener elements or the contact between the continuousfastener element and the slider when the slide fastener is opened orclosed. Therefore, even when the slide fastener is repeatedly cleaned orthe slider is repeatedly opened or closed, it is possible to sustain theeffect of the lubricating material and smoothly perform the slidingaction of the slider or the engaging action of the element rows for along period of time.

On the other hand, Japanese Patent Application Laid-Open No. 2005-160667(Patent Document 4) discloses a configuration in which a plurality ofindependent fastener elements are fixed to a fastener tape byinjection-molding even the fastener tape using, for example, a syntheticresin, wherein minute uneven portions are formed on the outer surface ofeach of the independent fastener elements, so that the outer peripheralsurface is finished into a pearskin of which a ten-point averageroughness is from 0.8 to 200 μm.

In Patent Document 4, the method of forming the uneven portions on theouter surfaces of the independent fastener elements is not particularlylimited. However, for example, a method is disclosed in which unevenportions are formed on a cavity surface of a mold used forinjection-molding to form minute uneven portions on the outer surfacesof the independent fastener elements.

Then, according to Patent Document 4, since the outer surface of theindependent fastener element is finished into the pearskin, light isirregularly reflected from the pearskin surface. For this reason, theslide fastener having the fastener element is dyed in the same bath todecrease a difference in the brightness between the fastener element andthe fastener tape, so that the fastener element and the fastener tapehave the same color tone.

Furthermore, in Patent Document 4, the shape of the slide fastener isnot particularly limited, and there is a description that a coil-shapedcontinuous fastener element molded from monofilament may be used as thefastener element in addition to the independent fastener element formedby the above-described injection molding.

Patent Document 1: Japanese Patent Application Publication No. 7-63411

Patent Document 2: Specification of Patent No. 3698562

Patent Document 3: Japanese Patent Application Publication No. 1-19888

Patent Document 4: Japanese Patent Application Laid-Open No. 2005-160667

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

When synthetic resinous monofilament is molded as a coil-shaped or azigzag-shaped continuous fastener element, peculiar gloss and luster ofthe monofilament are generally applied to the obtained continuousfastener element. However, when the slide fastener having the continuousfastener element with such gloss and luster is attached to products suchas bags, shoes, and clothes, gloss and luster of the continuous fastenerelement are too outstanding in accordance with the design of theproduct, so that they do not match the design of the product.

Furthermore, in order to solve the problem relating to gloss and lusterof the continuous fastener element, a method may be supposed in which aplurality of minute recesses are formed on the entire outer peripheralsurface of the continuous fastener element to reduce or remove gloss andluster of the continuous fastener element.

For example, although the purpose is different, minute recesses may beformed on the entire outer peripheral surface of the continuous fastenerelement by using the method disclosed in Patent Document 3, so thatgloss and luster of the continuous fastener element may be reduced orremoved. Further, in Patent Document 4, the specific manufacturingmethod is not described, but there is a description that uneven portionsmay be formed on the outer peripheral surface of the continuous fastenerelement or the like molded from the monofilament.

However, when minute recesses are formed on the entire outer peripheralsurface of the continuous fastener element in this manner, for example,when the slider is slid to open or close the slide fastener, theresistance between the slider and the continuous fastener element or theresistance between the coupling heads of the left and right continuousfastener elements increases. Accordingly, there is a problem that thesliding action of the slider becomes difficult and the operability ofthe slide fastener is degraded.

The invention is made in view of such circumstances of the backgroundart, and the specific object is to provide a continuous fastener elementcapable of reducing or removing peculiar gloss and luster ofmonofilament and suppressing a degradation of the operability of a slidefastener when the slide fastener is formed and a fastener stringerhaving the continuous fastener element.

Means for Solving the Problem

In order to achieve the above object, the invention provides acontinuous fastener element formed by molding thermoplastic syntheticresinous monofilament in a coil shape or a zigzag shape, the continuousfastener element including: a coupling head; upper and lower legportions which extend from the coupling head in the width direction; anda connecting portion which connects the leg portions adjacent to eachother in the longitudinal direction, being characterized in thatsurfaces of the coupling head, the leg portions, and the connectingportion are each formed as a rough surface with a plurality of recesses,and a head surface of the coupling head is formed to have an averageroughness Ra smaller than that of outer peripheral surfaces of the legportions.

In the continuous fastener element according to the invention, theaverage roughness Ra of the head surface of the coupling head ispreferably 90% or less of the average roughnesses Ra of the outerperipheral surfaces of the leg portions.

Particularly, the outer peripheral surfaces of the leg portions arepreferably each formed to have the average roughness Ra equal to or morethan 0.1 μm and equal to or less than 100 μm, and the head surface ofthe coupling head is preferably formed to have the average roughness Raequal to or more than 0.05 μm and equal to or less than 20 μm.

In the continuous fastener element according to the invention, an outerperipheral surface of the connecting portion is preferably formed tohave an average roughness Ra smaller than those of the outer peripheralsurfaces of the leg portions, in which case the average roughness Ra ofthe connecting portion is preferably 90% or less of the averageroughnesses Ra of the leg portions.

Particularly, an outer peripheral surface of the connecting portion ispreferably formed to have an average roughness Ra equal to or more than0.05 μm and equal to or less than 20 μm.

Furthermore, according to the invention, the fastener stringer havingthe continuous fastener element with the above-described configurationis provided.

Next, the method of manufacturing the continuous fastener elementaccording to the invention is mainly characterized in that it includes:an extruding process of extruding a thermoplastic synthetic resinousmaterial to mold linear monofilament; a roughening process of rougheningan outer peripheral surface of the monofilament; and an element moldingprocess of molding the roughened monofilament in a coil shape or azigzag shape and pressing a part of the monofilament at a constantinterval to mold a coupling head or of pressing a part of the roughenedmonofilament at a constant interval to mold a coupling head and moldingthe monofilament in a coil shape or a zigzag shape, wherein a part ofthe monofilament is heated and pressed when the coupling head is moldedin the element molding process, so that the coupling head is molded andan average roughness Ra of an outer peripheral surface of the couplinghead is made smaller than those of outer peripheral surfaces of the legportions.

In the method of manufacturing a continuous fastener element accordingto the invention, in the element molding process, the monofilament ispreferably heated and molded in a coil shape or a zigzag shape.

Furthermore, in the roughening process, the outer peripheral surface ofthe monofilament may be roughened in a manner such that the abrasivematerial is blasted from the blast nozzle to the monofilament or themonofilament is guided between the plurality of polishing rollers tocome into slid-contact with the polishing surfaces of the polishingrollers.

Effect of the Invention

In the coil-shaped or the zigzag-shaped continuous fastener elementaccording to the invention, the plurality of recesses are formed on thesurfaces of the coupling head, the leg portion, and the connectingportion, that is, the entire outer peripheral surface of the continuousfastener element, the entire outer peripheral surface is formed as therough surface, and the head surface of the coupling head has the averageroughness Ra smaller than that of the outer peripheral surface of theleg portion.

When the recesses are formed on the entire outer peripheral surface ofthe continuous fastener element, peculiar gloss and luster of themonofilament may be easily reduced or removed from the continuousfastener element. Further, since the head surface of the coupling headhas the average roughness Ra smaller than that of the leg portion, whenthe slide fastener is formed by using the continuous fastener element,the left and right element rows may be smoothly engaged or disengaged toor from each other since the resistance between the coupling heads ofthe left and right continuous fastener elements may be made small.Furthermore, the average roughness Ra of the invention is measured onthe condition that a cut-off value is 0.08 mm on the basis of JIS B0601.

In the continuous fastener element of the invention, the averageroughness Ra of the head surface of the coupling head is set to be 90%or less, and desirably, 60% or less of the average roughness Ra of theouter peripheral surface of the leg portion. Accordingly, even when therecesses are formed on the outer peripheral surface of the leg portionto remove gloss and luster from the continuous fastener element, it iseasily possible to decrease the resistance between the coupling heads ofthe left and right continuous fastener elements when the slide fasteneris formed.

In this case, since the outer peripheral surface of the leg portion hasthe average roughness Ra equal to or more than 0.1 μm and equal to orless than 100 μm, gloss and luster of the continuous fastener elementmay be reliably reduced or removed. Further, since the head surface ofthe coupling head has the average roughness Ra equal to or more than0.05 μm and equal to or less than 20 μm, the resistance between thecoupling heads of the left and right continuous fastener elements may bereliably decreased.

Further, in the continuous fastener element of the invention, the outerperipheral surface of the connecting portion has the average roughnessRa smaller than that of the outer peripheral surface of the leg portion,and particularly, the average roughness Ra of the connecting portion isset to be 90% or less, and desirably, 60% or less of the averageroughness Ra of the leg portion. Accordingly, when the slide fastener isformed by using the continuous fastener element, the resistance betweenthe continuous fastener element and the slider may be decreased. Forthis reason, the left and right element rows may be easily engaged ordisengaged to or from each other by smoothly sliding the slider alongthe element row.

In this case, since the outer peripheral surface of the connectingportion has the average roughness Ra equal to or more than 0.05 μm andequal to or less than 20 μm, the resistance between the continuousfastener element and the slider may be reliably decreased.

Further, in the fastener stringer of the invention having the continuousfastener element with the above-described configuration, gloss andluster of the continuous fastener element are reduced or removed, andthe resistance between the coupling heads of the left and rightcontinuous fastener elements is small, so that the left and rightelement rows may be smoothly engaged or disengaged to or from eachother. For this reason, the slide fastener obtained by using thefastener stringer may be suitably used for, for example, the productswhich do not match the design due to peculiar gloss and luster of themonofilament.

Next, the method of manufacturing the continuous fastener elementaccording to the invention includes the extruding process of extrudingand molding the linear monofilament, the roughening process ofroughening the outer peripheral surface of the monofilament, and theelement molding process of molding the roughened monofilament into acoil-shaped or a zigzag-shaped continuous fastener element. Furthermore,in the element molding process, a part of the monofilament is heated andpressed when the coupling head is molded.

According to the manufacturing method of the invention, it is possibleto easily and stably manufacture a coil-shaped or a zigzag-shapedcontinuous fastener element in which recesses are formed on surfaces ofa coupling head, a leg portion, and a connecting portion and a headsurface of the coupling head has an average roughness Ra smaller thanthat of the outer peripheral surface of the leg portion.

Further, in the invention, the monofilament is heated and molded in acoil shape or a zigzag shape in the element molding process.Accordingly, the average roughness Ra of the surface of the couplinghead of the obtained continuous fastener element may be reliably madesmaller than the average roughness Ra of the outer peripheral surface ofthe leg portion, and the average roughness Ra of the outer peripheralsurface of the connecting portion may be easily made smaller than theaverage roughness Ra of the outer peripheral surface of the leg portion.

Furthermore, in the roughening process, the outer peripheral surface ofthe monofilament is roughened in a manner such that the abrasivematerial is blasted from the blast nozzle to the monofilament or themonofilament is guided between the plurality of polishing rollers tocome into slide-contact with the polishing surfaces of the polishingrollers. Accordingly, the outer peripheral surface may be easily formedas a rough surface by forming the plurality of recesses on the outerperipheral surface of the monofilament.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a continuous fastener elementaccording to the invention.

FIG. 2 is a cross-sectional view illustrating a slide fastener havingthe continuous fastener element.

FIG. 3 is a cross-sectional view taken along the line shown in FIG. 2.

FIG. 4 is a flowchart illustrating a method of manufacturing thecontinuous fastener element according to the invention.

FIG. 5 is a schematic diagram illustrating a device for roughening anouter peripheral surface of monofilament in a roughening process.

FIG. 6 is a schematic diagram illustrating another device for rougheningthe outer peripheral surface of the monofilament in the rougheningprocess.

FIG. 7 is a schematic diagram illustrating a device for molding acontinuous fastener element in an element molding process.

FIG. 8 is a schematic diagram illustrating an existing stamp-moldingdevice.

EXPLANATIONS OF LETTERS AND NUMERALS

10 continuous fastener element

11 coupling head

11 a measurement area of average roughness Ra

12 upper leg portion

12 a measurement area of average roughness Ra

13 lower leg portion

14 connecting portion

14 a measurement area of average roughness Ra

20 slide fastener

21 core thread

22 fastener tape

23 sewing thread

24 element row

25 fastener stringer

26 slider

31 extruding process

32 roughening process

33 element molding process

36 polishing roller

37 monofilament

38 blast nozzle

39 abrasive material

41 winding portion

41 a mandrel

42 element molding portion

42 a screw

42 b coupling head forming portion

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the invention will be described in detailby referring to the drawings. Furthermore, the invention is not limitedto the embodiment to be described below, but may be modified intovarious forms so long as the same configuration and effect as those ofthe invention are obtained.

For example, a continuous fastener element to be described in theembodiment below is formed by molding monofilament in a coil shape, butthe invention is not limited thereto. The continuous fastener elementmay be formed by molding monofilament in a zigzag shape.

Here, FIG. 1 is a perspective view illustrating the continuous fastenerelement of the embodiment. Furthermore, in the description below, theelement length direction indicates a length direction of a fastener tapewhen a fastener stringer is formed by using the continuous fastenerelement, and the element width direction indicates a width direction ofa fastener tape.

A continuous fastener element 10 of the embodiment is formed by moldingmonofilament composed of a thermoplastic synthetic resin such aspolyamide or polyester to have a coil shape, and includes a flatcoupling head 11, an upper leg portion 12 and a lower leg portion 13which respectively extend from the coupling head 11 in the element widthdirection, and a connecting portion 14 which connects the upper legportion 12 (or the lower leg portion 13) of the continuous fastenerelement 10 to the lower leg portion 13 (or the upper leg portion 12) ofanother continuous fastener element 10 adjacent to the continuousfastener element in the element length direction.

Furthermore, when the coupling head 11, the upper leg portion 12, thelower leg portion 13, and the connecting portion 14 mentioned in theinvention are strictly defined, the coupling head 11 indicates a portioncontacting at least opposite coupling head 11 and contacting a guidepost of a slider 26. Further, the connecting portion 14 indicates aportion contacting the flange of at least the slider 26, and the upperleg portion 12 and the lower leg portion 13 indicate portions other thanthe coupling head 11 and the connecting portion 14.

Further, a plurality of recesses are provided on the entire surface ofthe continuous fastener element 10, so that the surface is formed as arough surface. The entire average value of the average roughness Ra ofthe continuous fastener element 10 is set to be equal to or more than0.05 μm and equal to or less than 100 μm, desirably equal to or morethan 0.05 μm and equal to or less than 20 μm, and more desirably equalto or more than 0.05 μm and equal to or less than 8 μm. Furthermore, theaverage value of the average roughness Ra mentioned herein indicates anaverage value of measurement values obtained when the average roughnessRa is measured at a plurality of positions (for example, 10 positions)of the continuous fastener element 10. In this manner, since the entireaverage value of the average roughness Ra of the continuous fastenerelement 10 is set to be 0.05 μm or more, gloss and luster of themonofilament may be effectively reduced or removed from the elementsurface.

Further, since the entire average value of the average roughness Ra ofthe continuous fastener element 10 is set to be 100 μm or less, themonofilament may be prevented from being disconnected when themonofilament is molded into the continuous fastener element 10. Further,as described below, since a force applied from an abrasive fabric or anabrasive material to the monofilament may be made small when the outerperipheral surface of the monofilament is roughened by a polishingtreatment or a blasting treatment in a roughening process 32, thequality (property) of the monofilament may be prevented from beingchanged in the roughening process 32 or the subsequent processes.Furthermore, the recess formed in the element surface (the outerperipheral surface) of the continuous fastener element 10 may be ahole-like recess or a groove-like recess, and the shape thereof is notparticularly limited.

Furthermore, in the continuous fastener element 10 of the embodiment,the average roughness Ra of the coupling head 11 is formed to bedifferent from the average roughnesses Ra of the upper and lower legportions 12 and 13. Further, the average roughness Ra of the connectingportion 14 is formed to be different from the average roughnesses Ra ofthe upper and lower leg portions 12 and 13. Especially, in this case,the surface (the outer peripheral surface) of the coupling head 11 andthe surface (the outer peripheral surface) of the connecting portion 14each has an average roughness Ra which is 90% or less and desirably 60%or less of the surfaces (the outer peripheral surfaces) of the upper andlower leg portions 12 and 13.

More specifically, in the embodiment, the average values of the averageroughnesses Ra of the upper and lower leg portions 12 and 13 are set tobe equal to or more than 0.10 μm and equal to or less than 100 μm,desirably equal to or more than 0.10 μm and equal to or less than 20 μm,and more desirably equal to or more than 0.10 μm and equal to or lessthan 8 μm. In this manner, since the average values of the averageroughnesses Ra of the upper and lower leg portions 12 and 13 occupying alarge area in the continuous fastener element 10 are 0.10 μm or more,gloss and luster of the surfaces of the leg portions may be effectivelysuppressed. Further, since the average values of the average roughnessRa of the upper and lower leg portions 12 and 13 are set to be 100 μm orless, as described above, the monofilament may be prevented from beingdisconnected and the quality of the monofilament may be prevented frombeing changed.

In particular, when the average values of the average roughnesses Ra ofthe upper and lower leg portions 12 and 13 are set to be 20 μm or less,as described below, it is possible to prevent a sewing thread 23 frombeing easily cut by the recess or the like of the element surface whenthe continuous fastener element 10 is sewn to a fastener tape 22 usingthe sewing thread 23.

Furthermore, when the average values of the average roughnesses Ra ofthe upper and lower leg portions 12 and 13 are set to be 8 μm or less,the outer peripheral surface of the monofilament to be molded in a coilshape may be relatively smoothly formed when the continuous fastenerelement 10 is manufactured. Accordingly, the monofilament may besmoothly delivered or carried, so that the monofilament may be stablymolded into the coil-shaped continuous fastener element 10 and adecrease in the yield rate may be prevented. Furthermore, in this case,the element manufacturing device molding the monofilament in a coilshape may be stably operated and the quality of the continuous fastenerelement 10 to be manufactured may be stabilized.

On the other hand, the average values of the average roughnesses Ra ofthe coupling head 11 and the connecting portion 14 of the continuousfastener element 10 are 90% or less (desirably 60% or less) of theaverage values of the average roughnesses Ra of the upper and lower legportions 12 and 13, and is set to be equal to or more than 0.05 μm andequal to or less than 20 desirably equal to or more than 0.05 μm andequal to or less than 10 μm, and more desirably equal to or more than0.05 μm and equal to or less than 4 μm.

In this manner, since the average values of the average roughnesses Raof the coupling head 11 and the connecting portion 14 are set to be 0.05μm or more, gloss and luster of the coupling head 11 and the connectingportion 14 may be suppressed. Further, since the average values of theaverage roughnesses Ra of the coupling head 11 and the connectingportion 14 are set to be 20 μm or less, as described below, when theslide fastener 20 is formed by using the continuous fastener element 10,the resistance between the left and right coupling heads 11 which easilycause a friction therebetween when opening or closing the slide fastener20 may be made small. Further, the resistance between the connectingportion 14 and the slider 26 of the continuous fastener element 10 maybe made small.

Then, when the slide fastener 20 shown in FIGS. 2 and 3 is formed byusing the coil-shaped continuous fastener element 10 of the embodiment,a core thread 21 is first inserted through the upper and lower legportions 12 and 13 of the continuous fastener element 10 along theelement length direction, and the continuous fastener element 10 is sewnto the tape side edge of the fastener tape 22 using the sewing thread 23while the core thread 21 is inserted therethrough. Furthermore, in FIG.2, the core thread 21 and the sewing thread 23 are not shown to easilyunderstand the characteristics of the continuous fastener element 10.

Accordingly, a pair of left and right fastener stringers 25 is obtainedwhich includes left and right element rows 24 having the continuousfastener element 10. Furthermore, the slide fastener 20 is formed byinserting the slider 26 into the left and right element rows 24 of theobtained fastener stringer 25. Furthermore, the slider 26 used in theslide fastener 20 of the embodiment has the same configuration as thegeneral slider used in the existing slide fastener.

The slide fastener 20 manufactured in this manner is formed so that theentire surface of the continuous fastener element 10 has a plurality ofminute recesses exposed on the surface, and the entire average value ofthe average roughness Ra of the continuous fastener element 10 is set tobe equal to or more than 0.05 μm and equal to or less than 100 μm.

For this reason, the slide fastener 20 does not have original gloss andluster of the monofilament in the continuous fastener element 10 and hastexture different from the existing general slide fastener. Therefore,the slide fastener 20 of the embodiment may be suitably used in productssuch as bags, shoes, and clothes which cannot be manufactured using theslide fastener with gloss and luster which do not match the designthereof.

Furthermore, in the continuous fastener element 10 disposed in the slidefastener 20, the average values of the average roughnesses Ra of theouter peripheral surfaces of the coupling head 11 and the connectingportion 14 are set to be 90% or less of the average values of theaverage roughnesses Ra of the outer peripheral surfaces of the upper andlower leg portions 12 and 13. For this reason, for example, when theleft and right element rows 24 engage with each other or disengage fromeach other by sliding the slider 26 along the element row 24, theresistance between the left and right coupling heads 11 may be madesmall and the resistance between the connecting portion 14 and theslider 26 of the continuous fastener element 10 may be made small.

Therefore, since the slider 26 may be smoothly slid along the elementrow 24 and the coupling heads 11 of the left and right continuousfastener elements 10 may be smoothly engaged with each other or theengaged left and right coupling heads 11 may be smoothly disengaged fromeach other, the operability of the slide fastener 20 may be improved.

Next, a method of manufacturing the continuous fastener element 10according to the embodiment will be described by referring to thedrawings.

Here, FIG. 4 is a flowchart illustrating the method of manufacturing thecontinuous fastener element 10. Further, FIG. 5 is a schematic diagramillustrating a device for roughening the outer peripheral surface of themonofilament in the roughening process 32.

First, in an extruding process 31 shown in FIG. 4, a meltedthermoplastic synthetic resinous material is extruded from an extrudingnozzle by using a generally known extruding unit, so that linearcontinuous monofilament is formed. The extruded monofilament is arrangedin a linear shape and is stretched by a predetermined magnificationratio in order to obtain a necessary diameter and a strong force.

Subsequently, the obtained monofilament undergoes the roughening process32. As shown in FIG. 5, the roughening process 32 is performed by adevice in which a plurality of polishing rollers 36 each having anabrasive fabric attached to the surface thereof are alternately disposedin the vertical direction. In this device, monofilament 37 is guidedbetween the upper and lower polishing rollers 36 from a supply portion(not shown) to come into slide-contact with the abrasive fabrics of thepolishing rollers 36 and each of the polishing rollers 36 is rotated inthe direction opposite to the guide direction of the monofilament 37, sothat a plurality of linear recesses are formed on the entire surface(the outer peripheral surface) of the monofilament 37.

In this case, the process conditions such as the number of the polishingrollers 36 or the type of the abrasive fabric are appropriately set sothat the average value of the average roughness Ra of the monofilamentafter the roughening process 32 is equal to or more than 0.10 μm andequal to or less than 100 μm, desirably equal to or more than 0.10 μmand equal to or less than 20 μm, and more desirably equal to or morethan 0.10 μm and equal to or less than 8 μm. Further, in order touniformly roughen the entire monofilament, the values of the processconditions may be fed back while rotating the monofilament 37 about theaxial direction.

Furthermore, the device or the method of forming the recess on theentire surface of the monofilament 37 in the roughening process 32 isnot particularly limited, but for example, the device or the like shownin FIG. 6 may be used instead of the device shown in FIG. 5. The deviceshown in FIG. 6 is configured to carry the monofilament 37 supplied froma supply portion (not shown) and blast an abrasive material 39 towardthe monofilament 37 from blast nozzles 38 disposed to be away from eachother in the vertical direction (or the horizontal direction) withrespect to the carriage path of the monofilament 37. Even using such adevice, a recess may be easily formed on the entire surface (the outerperipheral surface) of the monofilament 37, so that the surface of themonofilament may be finished into a pearskin.

Next, an element molding process 33 is performed which molds themonofilament 37 roughened in the roughening process 32 in a coil shapeand presses the monofilament 37 to mold the coupling head 11. In theelement molding process 33, for example, the device disclosed in PatentDocument 1 or Patent Document 2 may be used.

The device disclosed in Patent Document 1 is not shown in the drawing,but as described above, the device includes a supply roller whichnormally supplies a constant amount of monofilament, a stamp-moldingportion which has a pair of molding rollers stamp-molding a couplinghead or the like in the monofilament supplied from the supply roller,and a coil-shaped element molding portion which includes a mandrelmolding the stamp-molded monofilament into a coil-shaped continuousfastener element.

When the monofilament supplied from the supply roller is first pressedat a predetermined pressing condition in the stamp-molding portion usingsuch a device, the pressed portion of the monofilament is plasticallydeformed, whereby the coupling head 11 may be molded at a constantinterval in the monofilament and the plurality of recesses formed on thesurface of the pressed portion may be decreased in size or a part of therecess may be removed.

Further, in this case, it is desirable to provide, for example, a firstmonofilament heater in the stamp-molding portion to heat themonofilament when the monofilament is pressed. Since such a firstmonofilament heater is provided, the monofilament may be pressed whilebeing heated when the stamp-molding portion presses the monofilament toform the coupling head 11. Accordingly, the recess formed in the pressedportion of the monofilament may be reliably decreased in size or a partof the recess may be more reliably removed.

Since the stamp-molding portion performs the above-described process,the coupling head 11 may be stably formed at a constant interval of themonofilament and the average roughness Ra of the outer peripheralsurface of the coupling head 11 may be decreased in size.

Subsequently, the monofilament with the coupling head 11 is wound aroundthe mandrel in a predetermined winding condition in the coil-shapedelement molding portion, so that the monofilament is bent at theportions of the coupling head 11 and the connecting portion 14 to bemolded in a coil shape, and the average roughnesses Ra of the outerperipheral surfaces of the coupling head 11 and the connecting portion14 may be made small by the bending process at the coupling head 11 andthe connecting portion 14.

Further, in this case, a passage is provided inside the mandrel of thecoil-shaped element molding portion to allow the core thread to passtherethrough, so that the core thread is inserted into the coil-shapedelement molding portion. Furthermore, it is desirable to provide, forexample, a second monofilament heater in the coil-shaped element moldingportion to heat the monofilament when the monofilament is wound.

Since the second monofilament heater is provided, the monofilament maybe bent while being heated when the coil-shaped element molding portionwinds the monofilament around the mandrel. For this reason, the recessformed in the bent portion of the monofilament may be reliably decreasedin size or a part of the recess may be more reliably removed.

Furthermore, in the element molding process 33, the pressing conditionof the stamp-molding portion or the winding condition of the coil-shapedelement molding portion and the heating condition of the monofilamentheater when the first and second monofilament heaters are provided areappropriately set so that the average roughnesses Ra of the outerperipheral surfaces of the coupling head 11 and the connecting portion14 after the element molding process 33 are equal to or more than 0.05μm and equal to or less than 20 μm, desirably equal to or more than 0.05μm and equal to or less than 10 μm, and more desirably equal to or morethan 0.05 μm and equal to or less than 4 μm.

For example, when the first and second monofilament heaters heat themonofilament, it is desirable to heat the monofilament, for example, ata temperature of 50° C. or more and particularly at a temperature equalto or more than 90° C. and equal to or less than 140° C. Accordingly,the average roughnesses Ra of the coupling head 11 and the connectingportion 14 may be effectively made small.

Furthermore, in the stamp-molding portion or the coil-shaped elementmolding portion, when the average roughness Ra can be controlled withinthe predetermined range by appropriately setting the pressing conditionof the stamp-molding portion or the winding condition of the coil-shapedelement molding portion without heating the monofilament, themonofilament heater may not be provided in the stamp-molding portion orthe coil-shaped element molding portion.

In this manner, the continuous fastener element 10 of the embodiment maybe easily obtained by performing the element molding process 33 usingthe device disclosed in Patent Document 1.

On the other hand, the continuous fastener element 10 of the embodimentmay be obtained by performing the element molding process 33 even usingthe device disclosed in Patent Document 2.

In this case, as shown in FIG. 7, the device includes a monofilamentsupply portion (not shown) which supplies monofilament, a windingportion 41 which winds the monofilament 37 around a mandrel 41 a in acoil shape, and an element molding portion 42 which molds the couplinghead 11 in the monofilament 37 wound around the mandrel 41 a.

The winding portion 41 of the device includes a rotary body (not shown),the rod-like mandrel 41 a, a core thread bobbin (not shown) whichsupplies the core thread 21, and a core thread drawing body (not shown)which draws out the core thread 21 from the core thread bobbin. Further,a core thread guide groove is formed in the mandrel 41 a to guide thecore thread 21 in a sliding manner throughout the entire length thereof.

In the winding portion 41, when the monofilament 37 is wound around themandrel 41 a in a predetermined winding condition, the monofilament 37may be bent at the portions of the coupling head 11 and the connectingportion 14 to be molded in a coil shape, and a plurality of recessesformed in the outer peripheral surfaces of the coupling head 11 and theconnecting portion 14 may be decreased in size or a part of the recessmay be removed by the bending process of the monofilament 37.

Further, in this case, it is desirable to provide, for example, a firstmonofilament heater (not shown) in the winding portion 41 to heat themonofilament 37 when the monofilament 37 is wound around the mandrel 41a. Since the first monofilament heater is provided, the monofilament 37may be bent in a coil shape while being heated, whereby the recessformed at the bent portion of the monofilament 37 may be more reliablydecreased in size or a part of the recess may be more reliably removed.

Subsequently, the element molding portion 42 of the device includes apair of left and right screws 42 a which is disposed with the mandrel 41a of the winding portion 41 interposed therebetween and upper and lowercoupling head forming portions 42 b which are disposed with the mandrel41 a interposed therebetween and form the coupling head 11 in thecoil-shaped monofilament 37. In the element molding portion 14, thecoupling head 11 may be molded by pressing the coil-shaped monofilament37 at a predetermined interval using the coupling head forming portion42 b while the coil-shaped monofilament 37 is carried along the mandrel41 a by the screws 42 a, and the plurality of recesses formed on thesurface of the pressed coupling head 11 may be further decreased in sizeor a larger number of recesses may be removed.

Further, in this case, it is desirable to provide, for example, a secondmonofilament heater (not shown) in the element molding portion 42 toheat the monofilament 37 when the coil-shaped monofilament 37 is pressedto form the coupling head 11. Since the second monofilament heater isprovided, the recess formed in the outer peripheral surface of thecoupling head 11 may be more reliably decreased in size or a part of therecess may be more reliably removed.

Furthermore, in the winding portion 41 or the element molding portion42, when the average roughness Ra may be appropriately controlled withina predetermined range by appropriately setting the winding condition ofthe winding portion 41 or the molding condition of the element moldingportion 42 without heating the monofilament 37, the monofilament heatermay not be provided in the winding portion 41 or the element moldingportion 42.

In this manner, the continuous fastener element 10 of the embodiment maybe easily obtained by performing the element molding process 33 evenusing the device disclosed in Patent Document 2.

Then, when the obtained continuous fastener element 10 of the embodimentis sewn to the tape side edge of the fastener tape 22 while the corethread 21 is inserted through the upper and lower leg portions 12 and 13thereof as described above, the pair of left and right fastenerstringers 25 is formed. Further, when the slider 26 is inserted throughthe left and right element rows 24 of the fastener stringers 25, theslide fastener 20 having the continuous fastener element 10 of theembodiment is manufactured.

EXAMPLES

Hereinafter, the invention will be more specifically described byreferring to examples, but the invention is not limited thereto at all.

Two types of continuous fastener elements 10 were manufactured bydifferent methods in the different conditions as below, and the qualityof the continuous fastener element 10 was estimated by obtaining theaverage values of the average roughnesses Ra of the leg portion, thecoupling head 11, and the connecting portion 14 of the obtainedcontinuous fastener element 10.

In order to manufacture the continuous fastener element 10, meltedpolyamide was first extruded from an extruding nozzle in the extrudingprocess 31 to form linear monofilament, and the monofilament wasstretched. In the extruding process 31, two monofilaments weremanufactured at the same extruding and stretching conditions.

Subsequently, the two obtained monofilament was made to undergo theroughening process 32. In the roughening process 32, the abrasivematerial 39 was blasted from the blast nozzle 38 to the monofilament 37while the monofilament 37 is carried by the device shown in FIG. 6, sothat a recess was formed on the entire surface of the monofilament 37.

At this time, the abrasive material was blasted to the two monofilamentsobtained in the extruding process 31 at different conditions, so thattwo monofilaments having different surface properties and states weremanufactured. Specifically, an abrasive material WA150 of a whitealundum with an average particle diameter of 70 μm was blasted from theblast nozzle 38 toward one monofilament (Example 1) at the blastpressure of 0.5 MPa, so that the surface of the monofilament wasfinished into a pearskin.

Further, an abrasive material WA240 of a white alundum with an averageparticle diameter of 57 μm was blasted from the blast nozzle 38 to theother monofilament (Example 2) at the blast pressure of 025 MPa, so thatthe surface of the monofilament was finished into a pearskin.

Next, the element molding process 33 was performed on each monofilamentsubjected to the roughening process 32 by using the device shown in FIG.7, so that the monofilament 37 was molded by the winding portion 41 ofthe device in a coil shape. Furthermore, the coupling head 11 was formedin the coil-shaped monofilament 37 by the element molding portion 42 ofthe device.

By performing the above-described processes, two types of continuousfastener elements 10 having different average roughnesses Ra weremanufactured.

Subsequently, the two types of obtained continuous fastener elements 10were visually observed, and the average value of the average roughnessRa of each of the upper leg portion 12, the coupling head 11, and theconnecting portion 14 was obtained. At this time, Talysurf S4Cmanufactured by Taylor Hobson, Inc. was used as a device measuring theaverage roughness Ra, and the average roughnesses Ra of respectiveportions in the direction perpendicular to the extruding direction ofthe monofilament were measured on the condition that the cut-off valuewas 0.08 mm and the measurement length was 0.4 mm. Further, the averagevalue of the average roughnesses Ra of the upper leg portion 12, thecoupling head 11, and the connecting portion 14 were obtained in amanner such that the average roughness Ra was measured three timesinside the areas 12 a, 11 a, and 14 a depicted by the imaginary lines ofFIG. 1 and the average value of the measurement values of the measuredaverage roughnesses Ra was calculated.

Here, regarding each of the continuous fastener elements 10 of Example 1and Example 2, the calculation results of the average values of theaverage roughnesses Ra of the upper leg portion 12, the coupling head11, and the connecting portion 14 and the maximum value and the minimumvalue of the average roughness Ra of each portion are respectively shownin Table 1 and Table 2 as below. Further, the same tables also show theresults obtained by calculating the ratio of the average values of theaverage roughnesses Ra of the coupling head 11 and the connectingportion 14 with respect to the average value of the average roughness Raof the leg portion.

TABLE 1 Average roughness Ra of continuous fastener element of example 1Upper leg portion Coupling head Connecting portion Average value ofaverage roughness Ra Maximum value of average roughness Ra Minimum valueof average roughness Ra Ratio with respect to average roughness Ra ofleg portion

TABLE 2 Average roughness Ra of continuous fastener element of example 2Upper leg portion Coupling head Connecting portion Average value ofaverage roughness Ra Maximum value of average roughness Ra Minimum valueof average roughness Ra Ratio with respect to average roughness Ra ofleg portion

As a result of visually observing the continuous fastener elements 10 ofExample 1 and Example 2, gloss and luster of the continuous fastenerelements 10 were scarcely found. Further, as shown in Table 1 and Table2, the average values of the average roughness Ra of the coupling head11 and the connecting portion 14 of the continuous fastener elements 10of Example 1 and Example 2 were decreased to be 90% or less, andparticularly, 60% or less of the average value of the average roughnessRa of the leg portion, and were decreased to be particularly 40% or lessin the embodiment. That is, it was found that the surfaces (the outerperipheral surfaces) of the coupling head 11 and the connecting portion14 were formed to be smoother than that of the leg portion.

Therefore, since the slide fastener 20 is formed by using the continuousfastener element 10 of Example 1 or the continuous fastener element 10of Example 2, gloss and luster of the continuous fastener element 10 issuppressed. Furthermore, the slide fastener 20 may be provided whichsmoothly engages or disengages the left and right element rows 24 to orfrom each other when the slider 26 is made to slide along the elementrow 24.

The invention claimed is:
 1. A method of manufacturing a continuous fastener element, comprising: an extruding process of extruding a thermoplastic synthetic resinous material to mold linear monofilament; a roughening process of roughening an outer peripheral surface of the monofilament; and an element molding process of molding the roughened monofilament in a coil shape or a zigzag shape and pressing a part of the monofilament at a constant interval to mold a coupling head or of pressing a part of the roughened monofilament at a constant interval to mold a coupling head and molding the pressed monofilament in a coil shape or a zigzag shape, wherein a part of the roughened monofilament is heated and pressed when the coupling head is molded in the element molding process, so that the coupling head is molded and an average roughness of an outer peripheral surface of the coupling head is made smaller than an average roughness of outer peripheral surfaces of upper and lower leg portions which extend from the coupling head in a width direction.
 2. The method of manufacturing a continuous fastener element according to claim 1, wherein in the element molding process, the roughened monofilament is heated and molded in the coil shape or the zigzag shape.
 3. The method of manufacturing a continuous fastener element according to claim 1, wherein in the roughening process, an abrasive material is blasted from a blast nozzle toward the monofilament to roughen the outer peripheral surface of the monofilament.
 4. The method of manufacturing a continuous fastener element according to claim 1, wherein in the roughening process, the monofilament is guided between a plurality of polishing rollers and is made to come into slide-contact with polishing surfaces of the polishing rollers to roughen the outer peripheral surface of the monofilament.
 5. The method of manufacturing a continuous fastener element according to claim 1, wherein the average roughness of the outer peripheral surface of the coupling head is 90% or less of the average roughness of the outer peripheral surfaces of the upper and lower leg portions.
 6. The method of manufacturing a continuous fastener element according to claim 1, wherein the outer peripheral surfaces of the leg portions are each formed to have the average roughness 0.1 μm or more and 100 μm or less. 